JSFiddle - React, Tailwind, and code Playground

HTML

<table>
<tr>
  <th>aaa</th>
  <th>bbb</th>
</tr>
<tr>
  <td>xxx</td>
  <td>yyy</td>
</tr>
</table>

CSS

table {
  width: 100%;
  border-collapse: collapse;
}

table th,
table td {
  border: 1px solid #ccc;
}